The present invention involves a low permeation sealing member for reducing permeation of hydrocarbons from a vessel. A method and an apparatus for storing and broadcasting PoC sessions are also provided. Any communications traffic involving the target SU results in an intercept by a satellite, which routes a copy of the intercepted communications to the requesting LEA, either directly or via an associated intercept facility. During execution of a block, a prediction generator may take a control point history and generate a prediction. Lift-out protection is provided in the upper mounting for the all-glass leaf in the closed position.